Dr_UNIX Well that's interesting. I wonder why not?
I do see now that I missed that the OP said 12-30 and I even quoted the statement. Oh well, I'm going to fall back on my ADHD without the H excuse! <grin>
And lets not get into the whether or not a 11 cog is needed thing. I use mine. 12 just sometimes doesn't provided me a comfortable downhill cadence. If they didn't make an 11 tooth cog, I'd be okay. I'd just coast more.